John Harper asks: "Can waterspouts form on lakes or rivers? Or do they only occur over the ocean?"
John, that's a good question.
For those who don't know what a waterspout is, think of it like a tornado over water. They have a similar structure to tornadoes-- air rushes upward, and wind at the ground or ocean surface swirls quickly and forms a vortex.
Typically waterspouts form over oceans and are more common in the Florida Keys and the Florida Gulf Coast. Weather spotters have found waterspouts across the Great Lakes and Utah's Great Salt Lake.
So John, the answer to you question is yes, they can form on lakes or rivers, although it is very rare.
One interesting thing to note is waterspouts do not suck up water. The water seen in the funnel cloud comes from droplets of condensation.